Recovery Of Cellulose And Bioethanol Production Through Integrated Pretreatment Of Corncob

Abstract

Corncob Is One Of The Ligno cellulosic Wastes That Contains A Sufficient Amount Of Cellulosic Material, Has Potential As A Feedstock For Fermentable Sugar, And Can Be Utilized For Bioethanol Production. It Required Appropriate Pretreatment Methods To Remove Recalcitrant Parts Of The Biomass (Lignin And Hemi cellulose), Maximizing Cellulose Recovery And Fermentable Sugars. In This Research Work, Microwave-Assisted Binary Alkaline (Naoh+Nh4oh) Pretreatment Was Employed Using Corncob Biomass To Enhance Cellulose Recovery, Fermentable Sugar, And Bioethanol Production. Response Surface Methodology (Rsm) With Central Composite Design (Ccd) Was Employed To Investigate Optimum Conditions For Microwave-Assisted Binary Alkaline Pretreatment Of Corncob. The Effects Of Three Parameters, Such As Alkaline Concentration (1?�?3%, V/V), Pretreatment Time (5?�?15 Min), And Biomass Loading Ratio (0.05-0.15 G/Ml), Were Evaluated To Increase The Cellulose Recovery And Hemicellulose Removal. Ftir And Xrd Analyses Were Used To Characterize The Samples. The Residues After The Pretreatment Were Hydrolyzed Using Dilute Sulfuric Acid At Concentrations Of 1%, 2%, 3%, And 4% At Temperatures (100 ??C, 110 ??C, 120 ??C, And 130 ??C) And Times (15, 30, 45, And 60 Min). Bioethanol Fermentation Was Carried Out At 30 ??C With 200 Rpm For 4 Days With The Selected Hydrolysates Using Saccharomyces Cerevisiae. The Maximum Cellulose Recovery And Hemicellulose Removal Were 92.6% And 83.8%, Respectively, At The Optimum Conditions Of Alkaline Concentration (2%, V/V), Biomass Loading Ratio (0.1 G/Ml), Pretreatment Time (10 Min), And 400w Microwave Power. An Overall Increase In Crystallinity Index From 37.29 To 56.41% Was Observed At The Optimum Condition. Moreover, Ftir Spectra Revealed The Removal Of Hemicelluloses And Lignin After Pretreatment. The Maximum Glucose Concentration Of 58.16 Mg/Ml Was Released At 120 ??C With An Acid Concentration Of 3% (V/V) For 45 Min Of Hydrolysis Time, And The Maximum Bioethanol Concentration Was 23.64 Mg/Ml. The Characterization Of The Bioethanol Product Was Performed By Ftir, Which Revealed O-H, C-O, And C-H Functional Groups Similar To Those Of Standard Ethanol. These Results Suggest That The Microwave-Assisted Binary Alk